Herbicidal composition

ABSTRACT

A herbicidal composition comprises an active ingredient having the formula ##STR1## wherein R 1  represents a C 1  -C 5  alkoxy group; R 2  represents hydrogen atom, or a C 1  -C 5  alkyl group.

BACKGROUND OF THE INVENTION

The present invention relates to novel herbicidal compositions. More particularly, it relates to herbicidal compositions which have excellent herbicidal effect without phytotoxicity to crop plants such as rice plant, wheat, vegetables, cotton, fruit-tree, soybean and mulberry.

Various herbicidal compositions have been proposed and practically applied. Thus, herbicidal compositions having desired herbicidal effect without phytotoxicity to crop plants have been further required.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide novel herbicidal compositions which have excellent herbicidal effect without phytotoxicity to crop plants especially rice plant wheat, vegetables, cotton, fruit-tree, soybean and mulberry.

It is another object of the present invention to provide herbicidal composition comprising an active ingredient having only one phenyl ring so as to prevent a residual property.

The foregoing and other objects of the present invention have been attained by providing a herbicidal composition comprising an active ingredient having the formula ##STR2## wherein R¹ represents a C₁ -C₅ alkoxy group; R² represents hydrogen atom, or a C₁ -C₅ alkyl group.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The compounds having the formula ##STR3## wherein R¹ represents a C₁ -C₅ alkoxy group; R² represents hydrogen atom, or a C₁ -C₅ alkyl group, can be produced by the process disclosed in Journal of Chemical Society page 2942-2947 (1954).

In the formula (I), R¹ is a C₁ -C₅ alkoxy group such as methoxy, ethoxy, propoxy, butoxy or pentoxy group; R² is H, or a C₁ -C₅ alkyl group such as methyl, ethyl, propyl, butyl or amyl group. The alkyl group in R¹ or R² can be straight or branched chain.

Various compounds having herbicidal activities have been reported. Any herbicidal effect of the compounds having the formula (I) have not been known and the compounds have not been practically utilized.

The herbicidal compositions of the present invention impart excellent selective herbicidal effects to various weeds especially weeds in paddy field such as Echinochloa crus-galli, Monochoria vaginalis, Ammannia multiflora, Cyperus serotinus, Sagittaria trifolia, Eleocharis kuroguwai, Eleocharis acicularis and weeds in up-land such as Digitaria adscendens, Chenopodium album var. centrorubrum, Capsella bursa-pastoris, Chenopodium album or Amaranthus ascendens.

The characteristic of the herbicidal composition of the present invention is to have excellent intergeneric selectivity, especially to control gramineous weeds such as Digitaria adscendens and Echinochloa crus-galli without phytotoxicity to gramineous crop such as rice plant and wheat.

The desired applications are a soil treatment and a water surface treatment. The herbicidal effect of the present invention is especially high in a pre-emergency treatment or a plumule treatment.

One or more compound having the formula (I) can be used as the herbicide in the original form. It is, however, preferable to apply the compound in the form of herbicidal compositions such as wettable powders, emulsifiable concentrates, dusts, granules etc. by admixing with an adjuvant such as various carriers, fillers, solvents, surfactants and stabilizers. It is also possible to combine with the other herbicide, an insecticide, a fungicide, a plant growth regulator etc.

The dose of the active ingredient of the herbicidal composition of the present invention is depending upon a method of the application and a time of the application and usually 10 to 300 g. preferably 20 to 200 g. of the compound (I) per 1 are.

The formulation of the herbicidal composition of the present invention will be further illustrated.

The compounds (I) can be uniformly mixed with or dissolved in suitable adjuvants such as solid carrier such as talc, bentonite, clay, kaolin, diatomaceous earth, silica gel, vermiculite, lime, siliceous sand, ammonium sulfate or urea; liquid carriers such as alcohols, dioxane, acetone, cyclohexanone, methyl naphthalene or dimethylformamide; surfactants as emulsifiers dispersing agents or wetting agents such as alkyl sulfate, alkylsulfonate, polyoxyethyleneglycol ethers, polyoxyethylenealkylaryl ethers such as polyoxyethylenenonylphenol ether or polyoxyethylenesorbitane monoalkylate; and carboxymethyl cellulose, gum arabic and other adjuvants.

    ______________________________________                                         Wettable powder:                                                               ______________________________________                                         Active ingredient:   5 to 95 wt. %                                             Surfactant:          1 to 20 wt. %                                             Solid carrier:       5 to 85 wt. %                                             ______________________________________                                    

The active ingredient is admixed with the solid carrier and the surfactant and the mixture is pulverized.

    ______________________________________                                         Emulsifiable concentrate:                                                      ______________________________________                                         Active ingredient:   5 to 95 wt. %                                             Surfactant:          1 to 40 wt. %                                             Liquid carrier:      5 to 90 wt. %                                             ______________________________________                                    

The active ingredient is dissolved in the liquid carrier and the surfactant is admixed.

    ______________________________________                                         Dust:                                                                          ______________________________________                                         Active ingredient:    0.5 to 10 wt. %                                          Solid carrier:       99.5 to 90 wt. %                                          ______________________________________                                    

The active ingredient is mixed with fine solid carrier and the mixture is pulverized.

    ______________________________________                                         Granule:                                                                       ______________________________________                                         Active ingredient:    0.5 to 40 wt. %                                          Solid carrier:       99.5 to 60 wt. %                                          ______________________________________                                    

Certain examples of the preparations of the herbicidal compositions will be illustrated, however, the kinds and the ratio of the adjuvants are not limited and can be varied from the conventional consideration of the herbicidal compositions.

    ______________________________________                                         Composition 1 (Emulsifiable concentrate):                                      ______________________________________                                         2,6-Dinitro-4-t-butylanisole                                                                           20 wt. parts                                           Hexane                  20 wt. parts                                           Xylene                  45 wt. parts                                           Emulsifier (Sorpol 900A: Toho Chem.)                                                                   15 wt. parts                                           ______________________________________                                    

These components were uniformly mixed to prepare an emulsifiable concentrate. The composition is applied after diluting with water.

    ______________________________________                                         Composition 2 (Wettable powder):                                               ______________________________________                                         2,6-Dinitro-4-isopropylanisole                                                                        50 wt. parts                                            Diatomaceous earth     25 wt. parts                                            Clay                   22 wt. parts                                            Emulsifier (Lunox R-1000-C:                                                                            3 wt. parts                                            Toho Chem.)                                                                    ______________________________________                                    

The components were uniformly mixed and pulverized to prepare a wettable powder. The composition is applied after diluting with water.

    ______________________________________                                         Composition 3 (Granule):                                                       ______________________________________                                         2,6-Dinitro-4-t-butylanisole                                                                         10 wt. parts                                             Bentonite             30 wt. parts                                             Talc                  55 wt. parts                                             ______________________________________                                    

The components were uniformly mixed and pulverized and then, kneaded with water and granulated, dried and seived to prepare granules. The composition is applied without a dilution.

EXPERIMENT 1 Herbicidal effect to weeds in paddy field

Each Wagner pot of 1/2000 are was filled with paddy field soil and seeds of Echinochloa crus-galli and Monochloria vaginalis were sown and stem and root of Cyperus serotinus and rice seedling (3 to 4 leaf stage) (Nipponbare) were transplanted and the pot was flooded. Four days after the transplantation, the emulsifiable concentrate of Composition 1 was diluted and applied by a soil treatment at a dose of 100 g. 50 g or 25 g of the active ingredient per 1 are. Forty days after treatment, the herbicidal effects and the phytotoxicities to rice plant were observed and rated as follows. The results are shown in Table 1.

    ______________________________________                                         Herbicidal Effect (percent of Dead weed leaves)                                Rate              Percent                                                      ______________________________________                                         0                 less than 4%                                                 1                 5 to 24%                                                     2                 25 to 44%                                                    3                 45 to 69%                                                    4                 70 to 94%                                                    5                 95 to 100%                                                   ______________________________________                                         Phytotoxicity                                                                  ______________________________________                                         -                 No damage                                                    +                 Only slight damage                                           ++                Slight damage                                                +++               Middle damage                                                ++++              Serious damage                                               x                 Dead                                                         ______________________________________                                    

As a reference, Benthiocarb emulsifiable concentrate comprising an active ingredient having the formula ##STR4## was used.

Note:

E.C. Echinochloa crus-galli

M.V. Monochoria vaginalis

C.S. Cyperus serotinus

                  TABLE 1                                                          ______________________________________                                                    Dose of              Phyto-                                                                         toxicity                                                  act. ing.                                                                             Herbicidal effect                                                                            to rice                                        Active ingredient                                                                           (g./are) E.C.   M.V.  C.S.  plant                                 ______________________________________                                         2,6-dinitro-4-t-butyl-                                                                      100      5      5     5    --                                     anisole      50       5      5     5    --                                                  25       4-5    5     4-5  --                                     2,6-dinitro-4-iso-                                                                          100      5      5     5    --                                     propylanisole                                                                               50       4-5    4-5   4-5  --                                                  25       4      4     5    --                                     2,6-dinitro-4-                                                                              100      5      3     4    --                                     methylanisole                                                                               50       3-4    1     2-3  --                                                  25       3      0-1   2    --                                     2,6-dinitro-4-n-                                                                            100      5      5     4    --                                     butylanisole 50       3      5     3    --                                                  25       2      4     2    --                                     2,6-dinitro-4-sec-                                                                          100      5      5     3    --                                     butylanisole 50       4-5    4-5   2-3  --                                                  25       4      4     0-1  --                                     2,6-dinitro-4-n-                                                                            100      5      5     4    --                                     butyl-1-ethoxy-                                                                             50       5      4-5   3-4  --                                     benzene      25       5      4-5   2    --                                     2,6-dinitro-4-sec-                                                                          100      5      5     3    --                                     butyl-1-ethoxy-                                                                             50       5      5     2-3  --                                     benzene      25       4-5    5     1    --                                     2,6-dinitro-t-butyl-                                                                        100      5      5     4    --                                     1-ethoxybenzene                                                                             50       5      5     2--3 --                                                  25       5      4-5   2    --                                     2,6-dinitro-4-n-                                                                            100      5      5     3    --                                     pentyl-1-ethoxy                                                                             50       5      4-5   2-3  --                                     benzene      25       4-5    5     2    --                                     2,6-dinitro-4-t-butyl                                                                       100      5      5     4    --                                     1-n-propoxybenzene                                                                          50       5      5     2-3  --                                                  25       5      5     1    --                                     2,6-dinitro-4-n-                                                                            100      5      5     4    --                                     propyl-n-butoxy-                                                                            50       5      5     3    --                                     benzene      25       4-5    4-5   2    --                                     2,6-dinitro-4-isopro-                                                                       100      5      5     3    --                                     pyl-1-butoxybenzene                                                                         50       4-5    4     2-3  --                                                  25       4      4-5   1    --                                     2,6-dinitro-4-sec-                                                                          100      5      5     3-4  --                                     butyl-1-n-butoxy-                                                                           50       5      5     2-3  --                                     benzene      25       5      5     1    --                                     2,6-dinitro-4-t-butyl-                                                                      100      5      5     4    --                                     1-n-butoxybenzene                                                                           50       5      5     3    --                                                  25       4-5    4-5   2    --                                     2,6-dinitro-4-n-pentyl-                                                                     100      5      5     4    --                                     1-n-butoxybenzene                                                                           50       5      5     2-3                                                      25       4-5    4-5   2    --                                     2,6-dinitro-4-methyl-                                                                       100      5      5     3-4  --                                     1-n-pentoxybenzene                                                                          50       4-5    5     3    --                                                  25       4-5    4-5   2    --                                     Benthiocarb  50       5      5     5    +++                                                 25       5      5     5    ++                                                    12.5   5      4     4-5  +                                      ______________________________________                                    

EXPERIMENT 2 Herbicidal effect to weeds in up-land

Each Wagner pot of 1/2000 are was filled with up-land soil and seeds of weeds of Echinochloa Crus-galli, Digitaria adscendens and Amaranthus ascendens and seeds of crops of soybeans, cucumber and wheat were sown in a depth of 1 cm. Next day, each diluted solution of the emulsifiable concentrate of each active ingredient was uniformly sprayed on the soil. Twenty days after the treatment, herbicidal effects and phytotoxicities to crops were observed and rates as those of Experiment 1. The results are shown in Table 2.

Note:

E.C. Echinochloa crus-galli

D.A. Digitaria adscendens

A.A. Amaranthus ascendens

SoB. Soybeans

CuC. Cucumber

Wt. Wheat

                  TABLE 2                                                          ______________________________________                                                   Dose                                                                           of                                                                             act.                                                                           ing.                                                                           (g./ Herbicidal effect                                                                           Phytoxicity                                        Active ingredient                                                                          are)   E.C.   D.A.  A.A.                                                                               SoB. CuC. Wt.                              ______________________________________                                         2,6-dinitro-4-t-                                                                           100    5      5    5    --   --   --                               butylanisole                                                                               50     5      5    4    --   --   --                                           25     4-5    4-5  4    --   --   --                               2,6-dinitro-4-iso-                                                                         100    5      5    5    --   --   --                               propylanisole                                                                              50     4-5    4-5  4    --   --   --                                           25     4      4    3-4  --   --   --                               2,6-dinitro-4-                                                                             100    5      3    3    --   --   --                               methylanisole                                                                              50     5      1    2    --   --   --                                           25     4      0-1  1    --   --   --                               2,6-dinitro-4-n-                                                                           100    4      3    2    --   --   --                               butylanisole                                                                               50     2      2    1    --   --   --                                           25     1      0-1  0-1  --   --   --                               2,6-dinitro-4-sec-                                                                         100    5      5    5    --   --   --                               butylanisole                                                                               50     5      5    4    --   --   --                                           25     4-5    4-5  4    --   --   --                               2,6-dinitro-4-n-                                                                           100    5      5    5    --   --   --                               butyl-1-ethoxy-                                                                            50     5      5    4    --   --   --                               benzene     25     4-5    4-5  4    --   --   --                               2,6-dinitro-4-sec-                                                                         100    5      5    5    --   --   --                               butyl-1-ethoxy-                                                                            50     5      4-5  4    --   --   --                               benzene     25     4-5    4    3-4  --   --   --                               2,6-dinitro-t-butyl-                                                                       100    5      5    5    --   --   --                               ethoxybenzene                                                                              50     5      5    4    --   --   --                                           25     5      4-5  2    --   --   --                               2,6-dinitro-4-n-pen-                                                                       100    5      5    5    --   --   --                               tyl-1-ethoxybenzene                                                                        50     5      5    4-5  --   --   --                                           25     4      4    3-4  --   --   --                               2,6-dinitro-4-t-butyl-                                                                     100    5      5    5    --   --   --                               1-n-propoxybenzene                                                                         50     5      5    3    --   --   --                                           25     5      4-5  2    --   --   --                               2,6-dinitro-4-n-                                                                           100    5      5    5    --   --   --                               propyl-n-butoxy-                                                                           50     4-5    4-5  4    --   --   --                               benzene     25     4      4-5  4    --   --   --                               2,6-dinitro-4-                                                                             100    5      5    5    --                                         isopropyl-1-                                                                               50     5      5    4                                               n-butoxybenzene                                                                            25     4-5    4-5  4                                               2,6-dinitro-4-sec-                                                                         100    5      5    5    --   --   --                               butyl-1-butoxyben-                                                                         50     5      4-5  4    --   --   --                               zene        25     4-5    4    3-4  --   --   --                               2,6-dinitro-4-t-                                                                           100    5      5    5    --   --   --                               butyl-1-n-butoxy-                                                                          50     4-5    4-5  4-5  --   --   --                               benzene     25     4      4    4    --   --   --                               2,6-dinitro-4-n-                                                                           100    5      5    5    --   --   --                               pentyl-1-butoxy-                                                                           50     5      5    4-5  --   --   --                               benzene     25     4-5    4-5  4    --   --   --                               2,6-dinitro-4-methyl-                                                                      100    5      5    5    --   --   --                               1-n-pentoxybenzene                                                                         50     5      5    4-5  --   --   --                                           25     4-5    4- 5 4    --   --   --                               2,4-dichlorophenyl-                                                                        25     4-5    5    5    +   ++   +++                               4-nitrophenyl-                                                                             12.5   4      4    4    +   +    +                                 ether                                                                          ______________________________________                                    

PREPARATION 1 2,6-Dinitro-4-t-butyl-1-n-propoxybenzene

Into 70 ml. of ethanol (absolute), 0.92 g. of sodium metal was dissolved and 6.0 g. (0.04 M) of 4-tert-butylphenol was added and then, 3.5 g. (0.044 M) of n-propylchloride was added. The mixture was refluxed for 20 hours and ethanol was distilled off and water was added. The reaction product was extracted with benzene and benzene layer was washed with 3% NaOH aqueous solution and with water and dehydrated over sodium sulfate and then, benzene was distilled off and a residue was distilled under a reduced pressure to obtain 4-tert-butyl-1-n-propoxybenzene. The product was dissolved into 6 ml. of glacial acetic acid and then, 12 ml. of fuming nitric acid (d=1.5) was added at 0° to 5° C. to react them for 1 hour and then, the reaction was continued at the ambient temperature for 1 hour at 35° to 40° C. for 4 hours. The reaction mixture was poured into ice water and the product was extracted with chloroform and washed with water, with 3% Na₂ CO₃ aqueous solution and with water and dehydrated over sodium sulfate and chloroform was distilled off and the residue was recrystallized from ethanol to obtain 4.5 g. (43%) of a pale yellow crystal. (melting point of 106° to 107° C.)

PREPARATION 2 2,6-Dinitro-4-n-propyl-1-n-butoxybenzene

Into 70 ml. of ethanol (absolute), 1.15 g. of sodium metal was dissolved and 6.8 g. (0.05 M) of 4-n-propylphenol was added and then, 11.0 g. (0.1 M) of n-butylbromide was added. The mixture was refluxed for 20 hours and ethanol was distilled off under a reduced pressure and water was added. The product was extracted with benzene and washed with 3% NaOH aqueous solution and with water and dehydrated over sodium sulfate and benzene was distilled and the residue was distilled under a reduced pressure to obtain 4-n-propyl-n-butoxybenzene. In 5 ml. of glacial acetic acid, 5.5 g. (0.025 g.) of 4-n-propyl-n-butoxybenzene was dissolved and 10 ml. of fuming nitric acid (d=1.5) was added and then, 10 ml. of 20% fuming sulfuric acid was added to react them at 0° to 5° C. for 1 hour, and then at a room temperature for 1 hour and at 35° to 40° C. for 4 hours. The reaction mixture was poured into ice water and the product was extracted with chloroform and the chloroform layer was washed with water, with 3% Na₂ CO₃ aqueous solution and with water and dehydrated over sodium sulfate and chloroform was distilled off and the residue was distilled off under a reduced pressure to obtain 1.6 g. (yield of 20.6%) of 2,6-dinitro-4-n-propyl-1-n-butoxybenzene. (boiling point of 170° to 172° C./1.5 mmHg). 

We claim:
 1. A method of controlling the growth of weeds, comprising:applying to said weeds a herbicidally effective amount of a composition comprising, as the active ingredient, a compound of the formula: ##STR5## wherein R¹ is C₁ -C₅ alkoxy, and R² is hydrogen or C₁ -C₅ alkyl in combination with a herbicidal adjuvant.
 2. A method of controlling the growth of weeds, comprising:applying a herbicidally effective amount of a composition comprising, as the active ingredient, a compound of the formula: ##STR6## wherein R¹ is C₁ -C₅ alkoxy, and R² is hydrogen or C₁ -C₅ alkyl in combination with a herbicidal adjuvant to the soil during the preemergent stage of growth of said weeds.
 3. The method of claim 1 or 2, wherein said composition is applied in an amount of 10-300 grams of said active ingredient per one are.
 4. The method of claim 3, wherein said composition is applied in a quantity of 20-200 grams of said active ingredient per one are.
 5. The method of claim 1 or 2, wherein said composition is in the form of a formulation selected from the group consisting of (a) 5-95 weight percent of said active ingredient, 1-20 weight percent of a surfactant and 5-85 weight percent of a solid carrier in the form of a wettable powder, (b) 5-95 weight percent of said active ingredient, 1-40 weight percent of a surfactant and 5-90 weight percent of a liquid carrier in the form of an emulsufiable concentrate, (c) 0.5-10 weight percent of said active ingredient and 99.5-90 weight percent of a solid carrier in the form of a dust, and (d) 0.5-40 weight percent of said active ingredient and 99.5-60 weight percent of a solid carrier in granular form.
 6. The method of claim 1 or 2, wherein said adjuvant is a solid carrier selected from the group consisting of talc, bentonite, clay, kaolin, diatomaceous earth, silica gel, vermiculite, lime, siliceous sand, ammonium sulfate and urea; a liquid carrier selected from the group consisting of alcohols, dioxane, acetone, cyclohexanone, methylnaphthalene and dimethylformamide; a surfactant selected from the group consisting of an alkyl sulfate, an alkyl sulfonate, a polyoxyethylene glycol ether, a polyoxyethylene glycol ether, a polyoxyethylene alkyl aryl ether, and a polyoxyethylenesorbitane monoalkylate; carboxymethylcellulose; or gum arabic.
 7. The method of claim 1 or 2, wherein said composition is in the form of a wettable powder, an emulsifiable concentrate, a dust, or a granular material. 